1. Field of the Invention
The present invention pertains to an implantable medical device, and more particularly, pertains to a programmer/interrogator for use with an implanted defibrillator, and includes a removable key which allows either full or limited functions of the programmer/interrogator.
2. Description of the Prior Art
During a surgical procedure involving the implantation of a defibrillator, it is often necessary to program various parameters of the device while it is still in the sterile field of the operating room. The presently available programmers are fairly large instruments and are not sterilizable. Since the typical transmitting distance of the programmer is only a few inches, it is necessary to invade the sterile field in order to use it during the implant procedure. To accommodate this need for use in the operating room, a part of the programmer containing the transmitting/receiving antenna, called a wand, is connected to the programmer via a long umbilical cord. In some cases, the wand can be sterilized. In other cases, it is placed within a long sterile plastic bag to isolate the wand, and to allow the surgeon to handle it. In either case, the surgeon must rely on another person outside the sterile field to manipulate the controls at his direction. This situation invites error, as the surgeon is usually unfamiliar with the programmer and normally cannot see the controls or display. The umbilical cord is usually coiled and pulls on the wand in an unsuitable fashion towards the programmer.
Most programmers serve a dual purpose, to transmit program data to the implanted device, and to receive data interrogated from the implanted device. In the program data transmission situation, the surgeon is setting up a mode of therapy while in the latter case, the surgeon is monitoring the settings or reviewing interrogated performance data from the implanted device and patient. The monitoring mode is used primarily as a follow-up tool to evaluate the implanted device and patient during subsequent office visits. This mode is very important for patients who have an implanted defibrillator because there is no other means available for evaluating the condition or effectiveness of the device. Normally, patients would therefore have to schedule periodic and frequent visits to their surgeon to have the device checked and would have to visit the surgeon whenever they suspect any anomaly. There are home follow-up devices for defibrillator patients which rely on electrocardiographic (EKG) data, but such methods are not suitable for defibrillator patients. There are no existing home follow-up devices for defibrillator patients.
The present invention overcomes the deficiencies of the prior art by providing a sterilizable keyed programmer/interrogator for a defibrillator whose operating data can be interrogated and electronically relayed to a surgeon's office.